"I put these in my Vtwin motorcycle in November. In March the bike quit running. Took it to a dealer and all he had to do to get it running was put normal plugs in it. Hope nothing permanently damaged. Told a friend about it after the fact and he described the same trouble with his Chevy truck. His mechanic said they burn extra hot and mess up the computer sensors."posted by: GOC Sensei on March 12, 2014

"I replaced my 10 year old ----- Platinum +4 spark plugs which I was still getting 38 MPG highway with over 225k miles. After replacing with E3, my MPG fell to 32 MPG highway. Disappointed to say the least. I'm returning and going back to a new set of +4's."posted by: MJ on December 19, 2011view all 8 reviews